"Really this is just the financial assets, so if we can exchange those shares for good value, it makes perfect sense for the economy to pay down the deficit and use the financial flexibility that gives us to invest in bits of our infrastructure that do need public expenditure behind them."

Some fear the move will lead to more UK railways being owned by foreign investors.

But the government's not worried.

It's all part of a plan to sell 20 billion pounds of assets over the next 6 years.

"The kinds of things we are looking at over the next 5 years, would include student loans, of which we have a very big portfolio. So at some point it makes sense for us again to sell those into the private sector. There's not need for the government to continue to own those."